Recent advances in engineering vascularized tissues

Creating artificial organs is a long-standing goal of tissue engineering and regenerative medicine, providing a potential alternative to organ donation without the complications arising from rejection. Growing complex, functional tissues has additional applications in cancer research, drug development, and disease modeling. One of the biggest obstacles researchers face is vascularization: functional tissues need functional networks of blood vessels.

Ren et al. described recent advances in engineering vascularized tissues, including both in vitro models and in vivo applications. They discussed promising approaches and future opportunities.

“While tissue engineering has emerged as a critical field for drug testing and therapeutic designs, vascularizing engineered tissues remains a long-standing challenge,” said author Yong Huang. “Thanks to technological advances, the field has advanced significantly, and the research community needs a timely review.”

Blood vessels come in a variety of shapes, from large arteries to micron-sized capillaries, and are made of multiple cell types that all contribute to the delivery and removal of oxygen and nutrients. Such complex networks require advanced technologies to create them. Engineering approaches can manufacture large vessels through casting or channel printing, and biological approaches can induce self-assembling capillary structures.

With these technologies, researchers can create generic tissue models, tumor models, and organ-specific models for the heart, lungs, and brain in vitro. The team outlined the unique considerations for each of these cases and their representative realizations. They also discussed in vivo applications with vascularized tissue grafts and concluded with opportunities for future research.

“The next big challenges may include the identification of biofabrication technologies and biomaterials to engineer complex vascularized tissues with tissue-specific characteristics,” said Huang.

Source: “Realizations of vascularized tissues: from in vitro platforms to in vivo grafts,” by Bing Ren, Zhihua Jiang, Walter Lee Murfee, Adam J. Katz, Dietmar Siemann, and Yong Huang, Biophysics Reviews (2023). The article can be accessed at https://doi.org/10.1063/5.0131972 .